1. Field of the Invention
The present invention relates generally to apparatuses for mixing electrolyte in batteries.
2. Description of the Related Art
Batteries are devices which have a chemical action and generate electromotive force. Particularly, batteries which are rechargeable are called secondary batteries.
As is well-known to those skilled in this art, in the batteries, lead peroxide (PbO2) is used as a positive pole, foamed lead (Pb) is used as a negative pole, and dilute sulfuric acid (H2SO2) is used as electrolyte.
Such a battery makes flow of current using a potential difference between the positive pole and the negative pole that are respectively formed of lead peroxide and lead, thus generating power for operating a load. Here, a casing of the battery is filled with the electrolyte in such a way that the surface of the electrolyte is higher than the upper ends of pole plates fixed in the casing of the battery.
With the passage of time after the electrolyte has been supplied into the casing, as the battery is rechargeably used, the electrolyte is layered according to specific gravity so that lower-specific-gravity electrolyte is disposed in an upper layer while higher-specific-gravity electrolyte goes down into a lower layer.
The layering of electrolyte means separation of electrolyte into multiple layers according to specific gravity. This is a general phenomenon which is caused by a difference in specific gravity under conditions of no convection.
However, the pole plates restrict the flow of electrolyte so that upper and lower portions of electrolyte cannot be smoothly mixed with each other, thus causing the electrolyte to be layered. That is, in the conventional battery, the layering of electrolyte makes the specific gravity of electrolyte around the lower portion of the pole plate assembly high. Because the concentration of higher-specific-gravity sulfuric acid solution is comparatively high, corrosion of the lower portions of the pole plates accelerates.
Furthermore, in the conventional battery, due to higher-specific-gravity electrolyte that is disposed in the lower portion of the battery in which the pole plate assembly is provided, the terminal voltage of the battery may be indicated higher than an actual degree of charge. Such overvoltage may cause insufficient charge in a typical charging method of vehicles or other machines in which charge voltage is adjusted to a predetermined voltage. Moreover, continuous use of the battery that is in the insufficient charge state also accelerates sulfation of the pole plates, thus reducing the lifetime of the battery.